Process for producing tetrahydrophthalimides

Abstract

A compound of the formula: ##STR1## wherein R is an isoproyl group or an n-amyloxycarbonylmethyl group, useful as a herbicide, is effectively produced by reacting a compound of the formula: ##STR2## wherein R is as defined above, with sulfuryl chloride or chlorine in a solvent in the presence of a dehydrohalogenating agent.

What is claimed is: 
     
       1. A process for producing a tetrahydrophthalimide of the formula: ##STR7## wherein R is an isopropyl group or an n-amyloxycarbonylmethyl group, which comprises reacting N-(5-substituted-2-fluorophenyl)-3,4,5,6-tetrahydrophthalimide of the formula: ##STR8## wherein R is as defined above with sulfuryl chloride or chlorine in a solvent in the presence of a dehydrohalogenating agent. 
     
     
       2. The process according to claim 1, wherein the reaction is carried out at a temperature of 10° to 100° C. 
     
     
       3. The process according to claim 1, wherein the sulfuryl chloride or chlorine is used in an amount of 1 to 7 equivalents based on the starting N-(5-substituted-2-fluorophenyl)-3,4,5,6-tetrahydrophthalimide. 
     
     
       4. The process according to claim 1, wherein the dehydrohalogenating agent is used in an amount of 0.001 to 1 equivalents based on the starting N-(5-substituted-2-fluorophenyl)tetrahydrophthalimide. 
     
     
       5. The process according to claim 1, wherein the dehydrohalogenating agent is an organic base or an inorganic base. 
     
     
       6. The process according to claim 5, wherein the organic base is pyridine, triethylamine, N,N-diethylaniline or dicyclohexylamine. 
     
     
       7. The process according to claim 5, wherein the inorganic base is sodium hydroxide, potassium hydroxide, sodium carbonate or potassium carbonate. 
     
     
       8. The process according to claim 1, wherein the N-(5-substituted-2-fluorophenyl)-3,4,5,6-tetrahydrophthalimide is the one produced by reacting N-(2-fluoro-5-hydroxyphenyl)-3,4,5,6-tetrahydrophthalimide with a halide of the formula:   R--X     wherein R is as defined in claim 1 and X is a chlorine atom, a bromine atom or an iodine atom.   
     
     
       9. The process according to claim 8, wherein the N-(2-fluoro-5-hydroxyphenyl)-3,4,5,6-tetrahydrophthalimide is the one produced by (a) reacting 3-amino-4-fluorophenol with 3,4,5,6-tetrahydrophthalic anhydride, or (b) reacting N-(2-fluoro-5-aminophenyl)-3,4,5,6-tetrahydrophthalimide with sodium nitrite to make the diazonium salt and hydrolyzing the resulting diazonium salt. 
     
     
       10. The process according to claim 9, wherein 3-amino-4-fluorophenol is the one produced by reacting 2-fluoro-5-aminoacetanilide with sodium nitrite to make the diazonium salt and hydrolyzing the resulting diazonium salt. 
     
     
       11. The process according to claim 9, wherein N-(2-fluoro-5-aminophenol)-3,4,5,6-tetrahydrophthalimide is the one produced by reducing N-(2-fluoro-5-nitrophenyl)-3,4,5,6-tetrahydrophthalimide. 
     
     
       12. The process according to claim 11, wherein N-(2-fluoro-5-nitrophenyl)-3,4,5,6-tetrahydrophthalimide is the one produced by reacting 2-fluoro-5-nitroaniline with 3,4,5,6-tetrahydrophthalic anhydride. 
     
     
       13. A compound of the formula: ##STR9## wherein Y is an isopropoxy group, an n-amyloxycarbonylmethoxy group, a hydroxyl group, a nitro group or an amino group.